They questioned whether the pope really meant to make a concession on condoms or whether his words had been misinterpreted by the media, and said they said they were awaiting a definitive statement from the Vatican.

Rightwing Catholics are not satisfied by the existing statement of the Vatican spokesman, Frederico Lombardi, who said the pope knew his comments – made in an interview for a book released today – would provoke intense debate. Lombardi said the pope meant his remarks to apply not just to male prostitutes but also other men, women and transsexuals.

The US has in the past been the scene of fierce debates between Catholic conservatives and liberals, often over birth control.

Philip Lawler, editor of the US-based Catholic World News, demanded the resignation of his counterpart at the Vatican newspaper, L'Osservatore Romano, which published part of the controversial interiew at the weekend.

Lawler, who is a conservative,denied there had been any change in Vatican policy.

"Pope Benedict has not changed the Church's teachings, or even intimated that they might be subject to change. The Holy Father has not called for a new debate on the morality of contraception. He has not suggested that condom use might sometimes be morally justifiable." Yet millions round the world think he has, Lawler wrote.

He blamed the pope's PR staff and L'Osservatore Romano. "With its gross mishandling of this very serious issue, the Vatican newspaper has given rise to a worldwide confusion on a very important moral issue – damage that it may take years of painstaking work to undo," he wrote.

There is confusion and uncertainty among Catholics in the US. The US Conference of Catholic Bishops, the main church body in America, has made no comment and carried no mention of the issue on its website today. But the silence will be difficult to maintain as priests face questions this weekend when members turn up for services.

John Haas, the president of the National Catholic Bioethics Centre in Philadelphia, which advises church leaders, hospitals and Vatican offices, told the Associated Press: "It's a mess. I'm not ready to say that the pope said what Lombardi said." Haas said he had fielded calls all day yesterday from bishops confused by Lombardi's comments.

But Professor Dennis Doyle, professor of religious studies at the University of Dayton, said he did not expect a split or even great debate because most Catholics had long ago made a distinction between the ideal and concessions made in everyday life on the use of condoms.

"It will not create eruptions. I think most Catholics are somewhere along a big spectrum. People at the extremes tend to be the noisiest," he said.

"There will be a media storm and it will lead to change in the future, but gradually."

Father James Martin, writing in America, the national Catholic weekly run by the Jesuits, welcomed the pope's comments. The church has not officially changed its position on condoms and birth control, he writes. "But the previously out-of-bounds discussion about whether condoms can be used as a means to prevent the spread of disease is now in-bounds. That is change, by any definition. And that change is a good one, for if it moves the conversation ahead, it may mean a further lessening of the spread of HIV/Aids and the prevention of death.